Self-Calibration of Precision XYθ_z Metrology Stages

Abstract

This chapter studies the on-axis calibration for precision XYθ z metrology stages and presents a holistic XYθ z self-calibration approach. The proposed approach uses an artifact plate, specially designed with XY grid mark lines and angular mark lines, as a tool to be measured by the XYθ z metrology stages. In detail, the artifact plate is placed on the uncalibrated XYθ z metrology stages in four measurement postures or views. Then, the measurement error can be modeled as the construction of XYθ z systematic measurement error (i.e. stage error), artifact error, misalignment error, and random measurement noise. With a new property proposed, redundance of the XYθ z stage error is obtained, while the misalignment errors of all measurement views are determined by rigid mathematical processing. Resultantly, a least squarebased XYθ z self-calibration law is synthesized for final determination of the stage error. Computer simulation is conducted, and the calculation results validate that the proposed scheme can accurately realize the stage error even under the existence of various random measurement noise. Finally, the designed artifact plate is developed and illustrated for explanation of a standard XYθ z self-calibration procedure to meet practical industrial requirements.

A double shift self-calibration method for micro XY stages

“…The proposed result is an analytical solution, which, in the absence of random measurement errors, decompose the measurement results into the plate deviations from the nominal geometry and the systematic stage errors. Several evolutions and inspired approaches have been proposed [8,9,10,11,12,13,14,15,16,17], including approaches dealing with coordinate measuring machines [9,13], rotary stages [14], and XY θ z stages [11].…”